When the dust settles on a tempestuous match, the finger-pointing stops and the bans are handed out, perhaps this will be the occasion when Chelsea made it clear their title aspirations are authentic. They rode their luck at times – discounting the own goal from Gary Cahill – and their opponents were entitled to be aggrieved about some of the refereeing decisions. Yet nobody could question the endurance of Antonio Conte’s men, their competitive courage and the tactical acumen of their manager. Unfortunately for them, the occasion will be remembered more for the collective lack of discipline in stoppage time when City, to put it bluntly, lost the plot. Sergio Agüero, having already served one suspension this season, can expect a four-game ban after his scything red-card challenge on David Luiz. That, however, told only part of the story as the two sets of players clashed by the touchline and Fernandinho could be in serious trouble after reacting to some provocation from Cesc Fàbregas by grabbing him by the neck, levering him towards the crowd and eventually pushing him over the advertising hoardings almost into the laps of the front row of spectators.Fernandinho wanted to prolong the argument even after being sent off and he, and City, might face further action when the Football Association studies the video replays and sees how stewards had to prevent it getting even more out of hand. Chelsea could also be fined given the number of players from the sides locking horns. To put it into context, the managers felt compelled to go on the pitch and Diego Costa, of all people, could be seen trying to calm down Fernandinho. Guardiola did at least recognise it was a shabby way to end the match – “I would like to apologise,” he said – but he was pushing his luck trying to argue that Agüero’s wild, two-footed challenge was not intentional and his own conduct was questionable, to say the least. At one point, late in the game, Guardiola could be seen sarcastically clapping the referee, Anthony Taylor, for giving City a free-kick, even punching the air and sticking up his thumbs to give his act an extra flourish. Guardiola insisted that he would never be disrespectful about referees in press conferences, but he had already done just that in front of a television audience stretching to millions. As for his apology, it was hardly uttered in the manner of someone who genuinely felt contrition or embarrassment. He was seething, no matter how determined he was not to criticise Agüero or Fernandinho directly.